Determination of Nicotine in Tobacco by Chemometric Optimization and Cation-Selective Exhaustive Injection in Combination with Sweeping-Micellar Electrokinetic Chromatography

Nicotine is a potent chemical that excites the central nervous system and refreshes people. It is also physically addictive and causes dependence. To reduce the harm of tobacco products for smokers, a law was introduced that requires tobacco product containers to be marked with the amount of nicotine as well as tar. In this paper, an online stacking capillary electrophoresis (CE) method with cation-selective exhaustive injection sweeping-micellar electrokinetic chromatography (CSEI-sweeping-MEKC) is proposed for the optimized analysis of nicotine in tobacco. A higher conductivity buffer (160 mM phosphate buffer (pH 3)) zone was injected into the capillary, allowing for the analytes to be electrokinetically injected at a voltage of 15 kV for 15 min. Using 50 mM sodium dodecyl sulfate and 25% methanol in the sweeping buffer, nicotine was detected with high sensitivity. Thus, optimized conditions adapted from a chemometric approach provided a 6000-fold increase in the nicotine detection sensitivity using the CSEI-sweeping-MEKC method in comparison to normal CZE. The limits of detection were 0.5 nM for nicotine. The stacking method in combination with direct injection which matrix components would not interfere with assay performance was successfully applied to the detection of nicotine in tobacco samples.

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A fast and efficient method for the study of caffeine levels in energy drinks using micellar electrokinetic chromatography (MEKC)

Food Science and Technology ◽

10.1590/s0101-20612012005000042 ◽

2012 ◽

Vol 32 (2) ◽

pp. 401-404 ◽

Cited By ~ 2

Author(s):

Cristiano Augusto Ballus ◽

Adriana Dillenburg Meinhart ◽

Carolina Schaper Bizzotto ◽

José Teixeira Filho ◽

Helena Teixeira Godoy

Keyword(s):

Micellar Electrokinetic Chromatography ◽

Brain Activity ◽

Low Cost ◽

Sodium Dodecyl ◽

Energy Drinks ◽

Electrokinetic Chromatography ◽

The Central Nervous System ◽

The Mean ◽

High Doses

Energy drinks are becoming popular in Brazil and in the world due to their stimulant properties. Caffeine is present in energy drinks with the aim of stimulating the central nervous system and intensifying brain activity. On the other hand, the ingestion of high doses of caffeine can cause undesirable symptoms such as anxiety and tachycardia. Therefore, it is necessary to monitor the caffeine content added to energy drinks to guarantee that the levels in the final product are in accordance with the labeling and within the legislation limits. The goal of this work was to validate a fast, efficient, and low-cost method for the determination of caffeine in energy drinks by micellar electrokinetic chromatography (MEKC). A total of seven brands were analyzed, each in three lots. The electrolyte was prepared with 50 mmol.L-1 of sodium dodecyl sulfate (SDS) and 10 mmol.L-1 of sodium carbonate (pH 11.0). The mean concentration of caffeine ranged from 122.8 to 318.6 mg.L-1. None of the brands had caffeine levels above the maximum limit. Considering the interval of confidence (95%), 72% of the samples had less caffeine than the amount informed on the product label.

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Analysis of Seven Biogenic Amines and Two Amino Acids in Wines Using Micellar Electrokinetic Chromatography

Applied Sciences ◽

10.3390/app9061193 ◽

2019 ◽

Vol 9 (6) ◽

pp. 1193 ◽

Cited By ~ 3

Author(s):

Chih-Ying Huang ◽

Yu-Xian Wang ◽

Xin-Zhi Wang ◽

Cho-Chun Hu ◽

Tai-Chia Chiu

Keyword(s):

Amino Acids ◽

Biogenic Amines ◽

Micellar Electrokinetic Chromatography ◽

Low Cost ◽

Background Electrolyte ◽

Sodium Dodecyl ◽

Fast Method ◽

Electrokinetic Chromatography ◽

Optimal Separation

A low-cost, simple, and fast method utilizing micellar electrokinetic chromatography for the simultaneous determination of seven biogenic amines and two amino acids was developed. A background electrolyte containing 5 mM phosphate buffer (pH 3.7) and 20 mM sodium dodecyl sulfate was used. The optimal separation of nine investigated analytes was achieved in 11 min, with limits of detection (S/N = 3) ranging from 0.11 to 0.61 µM. The linear ranges for all analytes were observed between 0.55 and 10.0 μM (R2 > 0.990). The developed approach was extended to the analysis of analytes in commercial wine and beer samples. The recoveries of the proposed method ranged from 98.8% to 115.6%.

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Determination of Regularly Distributed Plant Protectants in Raw and Drinking Waters, Using a Multiresidue Method with Cyclodextrin-Modified Micellar Electrokinetic Chromatography

Journal of AOAC International ◽

10.1093/jaoac/82.6.1510 ◽

1999 ◽

Vol 82 (6) ◽

pp. 1510-1522 ◽

Cited By ~ 3

Author(s):

Hanno Stutz ◽

Hans Malissa

Keyword(s):

Environmental Protection Agency ◽

Micellar Electrokinetic Chromatography ◽

Solid Phase ◽

Tap Water ◽

Sodium Dodecyl ◽

Electrokinetic Chromatography ◽

The European Union ◽

Multiresidue Method ◽

Drinking Waters ◽

Wide Range

Abstract Eighteen plant protectant compounds were separated and determined by cyclodextrin-modified micellar electrokinetic chromatography (MEKC) in a multiclass/multiresidue method. The pesticides included are those dispersed in the greatest amounts today over agricultural acreage, and they represent 8 different classes of compounds (azoles, benzoic acids, chloroacetanilides, phenoxy acids, phenylureas, sulfonylureas, thiocarbamates, and triazines) covering a wide range of chemical reactivities and physicochemical properties. A 500 mL sample of tap water is preconcentrated by solid-phase extraction (SPE) with 300 mg combined polystyrene-divinylbenzene and methacrylate macroporous resins. Trapped analytes are eluted collectively with diethyl ether. Concentration and solvent change yield 250 μL of an acetone “concentrate,” which is further worked up and concentrated 1:10 to produce the MEKC injection solution containing 10 mmol/L sodium dodecyl sulfate (SDS) surfactant. For MEKC,2 phosphate/SDS buffer systems were designed, each allowing complete separation of all pesticides in a single run. Sensitivity was enhanced by a self-etched bubble cell and an injection procedure which employs stacking at reversed polarity. The ability of MEKC to determine plant protectants in raw and drinking waters at the 0.1 μg/L level, as demanded by the guidelines of the European Union, was demonstrated with spiked tap waters. Recoveries were between 75 and 110%, and limits of quantification, evaluated as method detection limits according to guidelines of the U.S. Environmental Protection Agency, ranged between 0.03 and 0.10 μg/L. The precisions of the relative migration times were all below 0.5%.

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